After Mt Keira teacher John Wren had both hips replaced, he thought he was fine. But he was being poisoned from within. Now, five years and five hips later, he is fighting to stay on this feet - just like 5000 other Australians who had the same implants.

John Wren knew he was on shaky ground when he "did the splits" on some wet concrete at work.

The nasty fall, on top of years of footy wear and tear, left him with painful unstable hips that needed replacing.

Like thousands of other Australians, the 57-year-old underwent hip replacement surgery and was enjoying his newfound mobility until a shocking letter two years after the 2008 surgery brought his world crashing down.

The makers of his DePuy ASR Hip Systems issued a recall due to data showing the systems are "defective in a disproportionate number of patients".

'Next thing I know I’m back talking to my specialist and having chromium and cobalt tests to see if I’ve got poisoning.'

Problems include the loosening of the implants within the body, but more frightening, reactions caused by the release of metal debris into the bloodstream.

"Everything fine, I was wagging my tail, then I get a letter from Johnson & Johnson representatives saying some of these hips were found to be faulty," Mr Wren said this week.

"Next thing I know I'm back talking to my specialist and having chromium and cobalt tests to see if I've got poisoning."

Mr Wren had elevated levels of chromium and cobalt and was forced to have his hips replaced.

He blames his deteriorating health today on the "poison" that seeped through his system before the hips were removed.

Back in 2008 Mr Wren was in a constant state of pain and couldn't work, play footy, surf, or live his life to the full.

So when a Sydney specialist advised the high school teacher and respected footy coach that he needed a double hip replacement, he tackled the setback head-on.

"I didn't want to be in pain any more," the Mount Keira man said.

"When the doctors told me I needed both of them done, I had a lot of damage and arthritic nodes on each hip. I thought 'OK, I'll take a respected doctor's word for it and take them both out in one go. I had both put in the same day, same time. The recovery was great. I couldn't get in and out of cars or up and down stairs before this. I thought 'this is great'. I had a new lease on life. I was back to normal in about 10 days."

One of Mr Wren's clinical reports noted: "failed metal on metal hip replacement has on rare occasions been associated with extremely high cobalt levels resulting in significant morbidity including deafness, blindness and heart failure which only improves with removal of the defective arthroplasty".

Mr Wren's levels were nowhere near that high at that point but reading the notes was certainly frightening.

"I thought 'gee this is scary'. When I read what it could do to you I knew I had to get them pulled out or my levels will keep rising," he said.

Mr Wren decided to replace one hip, and then wait six months to have the second surgery.

"For that six-month wait I was scared of the unknown, the consequences of heavy metal poisoning," he said.

"It's left its mark. No-one can say for sure, but I've got a heart problem - atrial fibrillation.

"Before hip number four they were going to put the operation off, to stop my heart and restart it, they thought they might not be able to do the surgery.

"I was five days in cardiac ward for tests on my heart before it went ahead."

Mr Wren believes the toxicity caused by the faulty hips has affected his sight and hearing.

"I've had a bleed behind [my] right eye and I've lost a fair amount of sight in that eye and I've had some hearing loss.

"At this stage I'm still all right … when they pulled out the toxic ones the levels dropped.

"They're back to normal or zero so I should be right now."

Replacing the two hips wasn't plain sailing.

The first operation was a success but the fourth new hip gave Mr Wren constant problems.

"Number three worked but then number four didn't. It kept dislocating.

"It springs apart inside your body, like a poltergeist, like you've been shot, the whole leg goes on you."

After five dislocations during rehab for number four, Mr Wren was allowed to go home but soon returned by ambulance from Wollongong to hospital in Sydney when his hip popped out again.

"They took out number four and gave me number five about six months ago," he said.

"I've had five hips in five years."

In Australia, DePuy, a member of the Johnson & Johnson family of companies, offered medical costs plus $33,000. In the US, $US250,000 ($265,000) has reportedly been made to eligible patients.

"Johnson & Johnson put their hand up and admitted liability, but after a big lawsuit in the US they have gone back into the bunkers."

Mr Wren is part of a class action, with close to 1500 group members registered.

The Federal Court trial has been adjourned to March next year and is listed for 16 weeks.

Shine lawyers represent about 600 group members - Maurice Blackburn and a number of South Australian firms represent the others.

The action is against the UK-based company DePuy International Ltd, which manufactured the DePuy ASR hip implants and against Johnson & Johnson Medical Pty Ltd, which distributed and sold the DePuy ASR hip implants within Australia.

It is alleged that the hip implants were defective, "not fit for their purpose" and were not of merchantable quality, in contravention of the Trade Practices Act 1974.

It is further alleged that DePuy and Johnson & Johnson were negligent.

Statistics maintained by the Australian Orthopaedic Association's National Joint Replacement Registry show that between 2003 and 2009 more than 5000 DePuy ASR implants were surgically implanted in Australia.

In December 2009 Johnson & Johnson withdrew the implants from sale in Australia.

In March 2010 Johnson & Johnson issued a safety alert in relation to the hip implants and in August 2010 it issued a hazard alert.

"It's a bloody worry. I've had to take medical retirement," he said.

"Some days are good, others are not so good - I can't even work one day in any government school or TAFE. I miss that. I like the camaraderie, the kids liked me and I like teaching.

"Now I've got a stamp on my forehead to never teach again. I'm still in shock over it really. And I'm unsure about what's going to happen in the future. I'm gun shy as to whether these hips will work."

Mr Wren has received no compensation but hopes companies involved come through.

"I was young, but I really feel for the older people who have had to go through this.

"It causes a lot of distress and the older you are the harder it is to recover.

"The idea that people knew about the problems with these hips back in 2006 and they were still using them two years later is not acceptable."